Coil-spring



v.' w KLIESRATH AND R. KNOPP.

COIL SPRING.

APPLICATVXON FILED FEB. 16. 1920.

1,365,701. Patented Jan. 18, 1921..

3 SHEETS-SHEET I.

m-van tozs V. W. KLI'ESRATH AND R. KNOPP.

COIL SPRING,

APPLICATION FILED FEB: 16, I920.

Patented Jan. 18, 1921.

3 SHEETS-SHEET 2.

V. W. KLIESRATH AND R. KNOPP.

' COIL SPRING.

APPLICATION HLED FEB. I6, 1920.

1,365,701; Patented Jan. 18,1921.

3 SHEETS-SHEET 3.

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AA A MW 9 35 mks; a km I I 8 u. Eikum UNITED STATES A TENT OFFICE.

VICTOR W. KLIESRATH, OF EAST ORANGE, AND

RUDOLPH KNOPP, OF MONTCLAIR,

NEW JERSEY, ASSIGNORS TO THE SIMMS MAGNETO COMPANY, OF EAST ORANGE, NEWJERSEY, A CORPORATION OF NEW JERSEY.

COIL-SPRING.

Original application filed May 31, 1919, Serial No. 301,129.

7 o all il /t 0 m it may concern Be it known that we, Vioron V. Knes-RAIII, a citizen of the United States, and lit'nonrn KNoPr, a, citizenof Austria, residing, respectively, at East Orange, in the county ofEssex and State of New Jersey, and Montclair, in the county of Essex andtitate of New Jersey, have invented certain new and useful Improvementsin Coil- S n'ings; and we do hereby declare the following to be a full,clear, and exact (1680111) tion of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

()ur invention consists in the novel features hereinafter described,reference being had to the accompanying drawing which illustrates oneembodiment of the same, selected by us for purposes of illustration, andthe said invention is fully disclosed in the following description andclaim.

This application is a division of our tormer applicatioi'i forimprovements in unpulse starter coupling filed May 31., 1.919, and givenSerial No. 301,129.

in the mimufacture of spiral torsional :qn'ings, it is customary to Wind:1 spring material about a mandrel to form a series or substantiallyconcentric spiral co' s, and the s 'irings are tempered and set so thatwhen completed, the coils are practically concentric. In the operationof such concentrically formed springs under variations oi? torsionalcompression and expansion, it is well known that they are extremely aptto break, and that the several coils are brought into contact usually ata number of points when the springs are wound or subjected to torsionalcompression. \Ve have found by experience that the effect of thiscontact be tween the coils of a spiral spring is to produce an unequalbending of the spring ma terial, some portions of the spring beingubjected to greater bending than others, together with a frictionalwearbetween the coils so forced .into contact, and further, we haveascertained by experiment and observation that when springs of this kindbreak, it is almost without exception at or adjacent to these points ofwear. This type of spring has always been more or less unsatisfactory inuse both on account of its liability to break,

Specification of Letters Patent.

According .coils tend to Patented Jan. 18, 1921.

Divided and this application filed February Serial No. 358,826.

whichappears to be due to a crystallization of the spring, due to theincreased bending strain adjacent to the points of contact, and alsobecause the frictional resistance between the coils retards the actionof the spring, and also prevents the spring from exercising its fullpower as it would do were it equally benttorsionally throughout itsentire extent and could exert the entire resilience of the spring body.

lVe have discovered that by forming a spiral spring in the mannerhereinafter described, all of these defects in the operation of spiralsprings can be avoided, and a practically unbrealmble spring can beproduced. to our invention, we term the spring in a series of successivecurved portions having diii'erent centers and diiierent radii, thelatter increasing from the inner end of the spring to the outer endthereot, and the said centers being located in difl erent radialdirections from the center of the innermost curved portion of thespring, and ordinarily within the innermost coil thereof. It follows,therefore, that when this spring is termed, tempered, and set, in themanner just described, its coils are composed througheutits length ofeccentrically curved portions oi the spring material, and when thespring is compressed torsionally, its

assume a more nearly concentric relation without coming in contact witheach other at any point in the length of the spring, so that the entireresilience of the entire length oi the spring is available at all.times; the spring always con'ipressed or bent equally throughout itsentire length, and there is no rubbing or frictional contact betweenadjacent coils, and consequentlly no retardation of the spring action,and no crystallization ot the material. during any ordinary use to whichthese s n-lugs have ever been subjected.

in the accompanying drawings we have shown one embodiment of ourimproved spring designed especially for use in connection with what istermed an impulse starter cou iling for magnetos, and it herein shownand described in connection therewith. It is to be understood, however,that the impulse starter coupling herein shown and described is notclaimed, but forms the subject matter of our former application abovereferred to, of which this application is a division.

Referring to the accompanying drawings which set forth an embodiment ofour invention selected by us for the purpose of illustrating the same,

Figure 1 represents a side elevation of our improved coupling, theposition of the magneto being indicated in dotted lines, and the dri*illg shaft being broken away.

Fig. 2 is a vertical sectional view of the same, the driving shaft beingremoved.

Fig. 3 is a detail perspective view showing the locking plate, thedriven member, the driving member, and other associated parts.

Fig. 4 is a vertical transverse sectional view on the line 4-4 of Fig.2, looking in the direction of the arrow Fig. 5 is a similar sectionalview taken on the line 5-5 of Fig. 2, and looking in the direction ofthe arrow.

Fig. 6 is a view similar to Fig. 5 illus trating the operation of one ofthe cams on the driving member in disengaging one of. the lockingdevices carried by the driven shaft.

Fig. 7 is a similar view showing the normal position of the lockinglevers when the parts are operating at normal speed, and said levers areheld out of operative position by centrifugal force.

Fig. 8 is a detail view of our improved spiral spring which we prefer toemploy in our improved coupling, as it appears after being formed,tempered, and set, and before being placed under compression.

In the accompanying drawings, 1 represents a stationary plate of anydesired form, provided with means, as screws for example, by which itmay be secured rigidly to the frame of a magneto, indicated at M, indotted lines in Figs. 1 and 2, the said plate be ing provided with acentral aperture through which the shaft of the magneto armatureindicated at m in Fig. 2, may pass. This stationary plate 1 ispreferably provided with an outwardly extending dust flange, indicatedat 2, and is also provided with an annular locking hub, indicated at 4,provided with a locking shoulder 5. For convenience of manufacture, weprefer to provide the locking plate 1 with a thin plate or stamping 3,carrying the annular dust flange 2, and to make the hub 4 separate fromthe plate and attach the hub 4, plate 3, and plate 1, together by meansof rivets, one of which is indicated at 6 in 2, or otherwise, but we donot limit ourselves to this construction. The plate 1 is shown providedwith screws, indicated in dotted lines at 7, for attaching it to theframe of the magneto, and it will be seen that the armature shaft m,which is preferably provided with a tapered portion, and an exteriorthreaded portion, projects through the central apertures in the plates 1andv 3 and hub 4. The driven member of our improved coupling comprises adisk 8 having a central. sleeve 9 projecting on both sides of the same,the inner end of the sleeve 9 being preferably tapered to it thetapering portion of the shoulder of the armature shaft in, and providedwith a keyway 10 to receive a key (not shown) for rigidly securing it tothe armature shaft.

On its inner face the disk 8 carries a pair of pivoted centrifugallycontrolled locking levers l111 pivoted at 12-12 to the disk 8. Each ofthese levers is provided with a lo -i-:- ing detent 13 located on oneside of its pivot and with a cam engaging portion '14 on the other sideof its pivot, and each of said levers is provided with an extension 15on the side of the pivot adjacent to the detent and projecting beyondthe detent, increasing the length of the lever on that side of its pointof pivoting, said extension 1515 acting as centrifugal weights towithdraw the lockin levers to their inoperative positions whenever thearmature shaft is being rotated at suflicient or predetermined speed, toproduce the desired spark. e prefer to construct the levers insubstantially the manner described with the weighted ends or extensionsprojecting beyond the locking detents and located at the opposite endsof the lever from their cam engaging portions 14. (inc advantage of thisconstruction is that by varying the length of the projecting portions15, the coupling may be readily adapted for use under circumstancesrequiring the niainlcnance of diflerent magneto speeds without varyingany other portion of the apparatus. In the accompanying drawings we haveshown our invention applied to a coupling intended for use with amagneto producing two sparks per revolution of the armature shaft, andas will be readily "illlvltlv iumi, either one of the locking levers 11may en gag the locking shoulder 5 of the locking hub 4, said shoulderbeing located on the upper side of the hub, so that the disk 8, and thearmature shaft in. with which it is rig idly connected, may be locked intwo :-l

tions at opposite points in the revolution thereof. The disk 8 is alsoprovided on its outer face with a stop lug or projection 16. andsegmental portions of said disk on opposite sides of the center are cutaway, as indicated at 171'7, to facilitate assembling the parts.

The driving member of the coupling comprises a disk 20 provided with asleeve 21 projecting from the inner face thereof and adapted to it overwith a bearing fit, and rotate upon the exterior portion of the Sleeve 9of the driven member. T he disk 20 is also provided with an annularhousing 22 which may be formed integrally with ion lliii i it) the disk,or may be formed separately and secured thereto, which housing extendswithin the annular recess formed by the dust flange 2 (see Fig. 2). Onits inner face the disk 20 is also provided with a stop lug 23 forengaging the stop lug 16 on the driven disk 8, and the driving disk 20is also provided, in this instance at points diametrically opposite toeach other, with cams 24-24, for engaging the ends 14-142 of the lockinglevers, and positively withdrawing them from locking position withrespect to the locking hub 4. These cams 24 may be formed in any desiredway, but we find it convenient to form them by indenting portions of thehousing 22, as shown best in Fi 3.

fietween the driving and driven members of the coupling we inter-pose aspring oi? peculiar construction, which we have found to be especiallydesirable for use in this device. In the formation of the ordinary siral springs, the spring material is coiled event a common center in theform of a spiral, or in other words, the coils have a constantlyincreasing radius. Such springs when placed under compression, havetheir coils forced into contact with each other at various points. Thisroduces two very objectionable results. n the relative movements of thespring coils when the Spring expands, a considerable amount of frictionis caused which materially retards the movement imparted by the springand makes it slower than would otherwise be the case. Again, the factthat the spring coils contact at various points interferes with anabsoluately uniform distribution of the stress through the entire lengthof the spring, and puts certain parts of the spring under greater stressthan others, with the result that the highly tempered material rapidlycrystallizes, and such springs are continu ally breaking. In ourimproved impulse starter coupling it is of greatest importance that thespring should not break, as the result would be to stop the operation ofthe magneto and the engine with which it is connected, and secondlvthere must be noth ing to interfere with the rapid motion imparted bythe spring, as one of' the principal objects of the coupling is toimpart very rapid movement to the armature shaft, and anything whichtends to slow this movement effected by the tension of the spring, tendsto defeat the operation of the device.

As a result of much study and experiment we have found that a springdesigned substantially as shown in detail in Fig. 8, being substantiallyeccentric throughout its entire extent and increasing the distancebetween adjacent coils, produces the most advantageous results in ourcoupling without any of the difficulties which have been heretoforeexperienced in the use of spiral springs,

but are located usually in the same plane. In forming this spring, wetake a rod or band (preferably a band) of spring mate rial and bend itinto the form shown in Fig. 8 for example, in which the several coils,substantially three coils being herein shown, are in the same plane andgradually increase in distance from each other and are bent into curvedform, successive portions of each coil being curved concentrically withor about totally different centers, disposed in different positionsradially with respect to the center of the innermost portion of theinner coil. I11 Fig. 8, for example, arrows are indicated leading fromten different centors in different directions to portions of the springcurved about or concentric therewith. lVc do not limit ourselves to theexact number of different and distinct centers which we may employ inlaying out this spring, or in the precise proportions of the length ofthe successive portions of the spring to be formed about or concentricwith each of said centers, as reasonable variations may be made in thesame within the limits of our invention, the essential feature of whichis that successive portions of the spring coils shall be curvedconcentrically with or about entirely different and distinct centers,substantially as in the manner shown in Fig. 8, so that when the springis coiled down and placed under its normal tension, every portion of thespring throughout its length shall be subject to the same tension, andso that the several coils will be equallydistant from each otherthroughout their entire length, as indicated for example in Fig. 4;, inwhich the spring 25 is shown under tension. Our improved spring isformed, tempered, and set in substantially the form shown in Fig. 8, andwhen given its required tension, it will assume substantially the formoil an ordinary spiral spring when tempered and set, be-

fore any tension is applied thereto, and the several centers will. bebrought into substantially concentric relation. Further compression of'our improved spring continue to distribute the strain uniforn throughoutthe entire length of the spri without distorting any of the coils, orbring ing any coil in frictional contact with another, and the springtherefore has no tendency to crystallize, and can at all times e1;-ercise its maximum resiliency with the re sult of securing the highestpossible speed of rotation. In other words, whereas '1- creased tensiontends to distort the coils of ordinary spiral spring out of concentricrelation and force the coils into contact with each other. our improvedspring is so constructed that increased tension tends to force its coilsinto a ;concentric relation which they do not have when formed, set, andtempered.

l ll 0 For convenience in inserting the spring 25, we conveniently rollup the ends of the spring to rm the cylindrical retaining portions36-27, which are connected respectively to the driving member and thedriven member 8. d e prefer to form a nearly cylindrical recess in thesleeve 21 01'? the driving member, to receive the end 26 ot the spring,and a similar recess 2%) is provided in the stop lug 16 of the dish 8 toreceive the other end 2'? of the spring, as clearly shown in Fig. l. llhen the parts are assembled, as shown in l, the normal tension of thespring tends to hold the stop lug 16 of the driven member or disk 8 incontact with the stop lug 523 of the driving member 20. In assemblingthe parts, the cut oil segments forming the straight sides 17 -17 of thedish 8 oermit the disk to be inserted within the housing past theopposite cams 2 l2l, as indicated in Fig. 5, and to pass beyond thesecams whicn are in the same plane a the lockin levers 11.

In assembling the parts a relt washer (see Fig. 2) is inserted withinthe dust flange 2, and a dustring, indicated. at 31, Fig. 2, is pressedon a reduced portion 22 of the housing 22, to engage the washer 30within the dust flange 2, thus ei fectually sealing the device againstthe ingress of dust or other extraneous matter. The parts can be held inoperative relation in any desired manner. in the present instance wehave shown a nut 32 screwed on the outer end of the sleeve 9 for holdingthe driving and driven members to ether, and have a so shown a hollowsleeve nut screwed on the threaded portion m for holding the sleeve 9firmly in engagement with the conical portion of the armatu e shaft. Thedriving member may be provided with any suitable means for connecting itwith the driving shaft, indicated in Fig. 1, at in the present instancewe have shown the outer face of the driving member or dish 20 providedwith a plurality of serrations or projections, indicated at 35, andbeing preterably twenty in number. Ti e have also shown the drivingshaft, which is ordinarily mounted in axial alinement with the shaft onof the magneto, provided with a driving collar 36, bored to fit theshaft, and split, as indicated at 37, and provided with a securing boltwhich preferably passes through tl e collar and shaft transversely ofthe split 3? in the collar, so as to clamp the collar on the shaft, 2*well as to secure it to rotate therewith. This collar is provided with aflange portion 39 of substantially the same diameter as the driving disk20, and has its inner face provided with a plurality of serrations orprojections l0, one less in number than the number of projections orserrations on the disk 20, in other words, in this instance havingnineteen projections. We

also provide an intermediate driving ring indicated at ll, which ispreferably made of resilient material such as vulcanized rubber, 01 thedesired degree of softness, which is provided on its inner face with aplurality oi serr tions or projections -12 of the same number as thoseol. the disk 20, for interchanging the same, and on its outer face isprovided with a plurality of serrations or projections 4L3 correspondingin number with those oi. the driving collar 36, and interchanging withthe same. o lind this construction desirable in that it provides aresilient connection between the driving shalt and the driving member ofthe coupling which will take up sudden shochs and and it also providesin eliicct what ma be termed a vernicr type oi adjustment. by means ofwhich the timing of the magneto with the engine may be ell ccte l so :Isto bring the instant of ignition ol the engine in proper timed relationwith the sparking positions of the armature.

Assuming that the parts are stationary, and it is desired to start theengine, the engine is rotated by hand or by a suitable starter in suchdirection as to impart move ment to the driving member 20 in thedirection of the arrows in Figs. and 5, it being understood that thesections represent ed in these figures are viewed from oppositedirections. The driven member 8 and the armature shaft m will be lockedfrom movement by the engagement oi? one of the locking levers 11 withthe locking hub l, as shown in Fig. 5. The rotation of the drivingmember 20 will cause the sleeve fill carrying the inner end of thespring to move in the direction of the arrows in Fig. 4-, and increasethe tension of the spring, and will also cause the stop lug 23 to moveaway from the stop lug 16, of the driven member. its the rotation oi thedriving mem her proceeds one of the cams Al; will he brought intoengagement with the end Ll; of the locking lever 11, in engagement withthe locking hub, thereby tripping said lcver, as shown in Fig. 6, andreleasing the driven member 8 of the coupling, which is then acted uponby the compressed spring 25 to effect a partial rotation at very highspeed to the armature shaft, also in the direction of the arrows in theseveral figures, until the stop lug 16 on the driven memher 8 catches upwith and engages the stop lug 23 on the driving member 20, thusimparting the necessary high speed to the magneto armature to produce astrong spark for ignition purposes. After a halt revolm tion the otherlever 11 will engage the locking hub 4;, locking the driven member and.armature shaft, when the operation just described is repeated. Thisoperation is repeated at every half revolution of the armature shaftuntil the driving shatt attains a sufiicient speed to cause the weightedends of the levers 11 to be acted upon by centrifugal force so as tohold said levers out of engagement with the locking hub 4 after whichthe driven member will be rotated at the same speed as, and with, thedriving member, the power being transmitted through the spring 25 underits normal compression or tension, said spring acting as a yieldingconnection between the driving and driven members under normal highspeed conditions. If for any reason the speed of the engine slows downto such a point that the locking levers 11 are no longer held out ofoperation by centrifugal force, the levels will successively engage thelocking hub a and the armature shaft will be driven by the series ofintermittent rapid impulses instead of by steady or continuous rotation,in the same manner as in starting.

While We have shown our improved sprin as applied to and forming part ofan iInpuFse starter coupling in order to illustrate its construction andoperation, it is to be understood that it may be used for any otherpurpose for which it may be found desirable or advantageous.

What we claim and desire to secure by Letters Patent is 1. As a newarticle of manufacture, a torsional spring, said spring when in expandedcondition, having successive portions throughout its length curved aboutdifferent centers located in different positions radially with respectto the center of the innermost curved portion of the spring, saidcenters being so disposed that when said spring is wound in a rotarydirection to compress the spring, all portions of the spring will besubstantially uniformly bent, and the centers of said successive curvedportions will be maintained substantially in concentric relation, andthe coils will be maintained out of contact with each other.

2. As a new article of manufacture, a torsional spring having aplurality of coils in substantially the same plane, said spring when inexpanded condition having successive portions curved about differentcenters, and located within the innermost coil of the innermost curvedportion of the spring, the several coils being separated differentdistances, increasing gradually from the inner end of the inner coil tothe outer end of the spring, whereby when said spring is wound in arotary direction to compress it, all portions thereof will besubstantially uniformly bent, and the said different centers of the saidsuccessive portions will be brought into, and maintained insubstantially concentric relation, and the coils will be held insubstantial parallelism.

3. As a new article of manufacture, a torsional spring having aplurality of coils, said spring when in expanded condition havingsuccessive portions curved about different centers located within theinnermost coil, and in different radial positions with respect to thecenter of the innermost portion of the inner coil, said successiveportions having radii of different lengths, the radii of successiveportions increasing from the inner end of the spring to the outer endthereof, whereby when said spring is com pressed in a rotary direction,all portions thereof will be substantially uniformly bent, and saiddifferent centers will be brought into, and maintained in substantiallyconcentric relation with respect to each other and the coil, and theseveral. coils of the spring will be brought into and maintained. insubstantial parallelism without contact at any point therein.

In testimony whereof we afl'ix our signatures.

'vioron w. KLIESRATH. RUDOLPH KNOPP.

